SUB-REGIONAL SCENARIOS

WESTERN AFRICA

Western Africa is made up of two eco-geographical
areas: first, the Sahel countries, including Burkina Faso,
Cape Verde, Gambia, Guinea-Bissau, Mali, Mauritania,
Niger and Senegal, which make up the dry region of
West Africa, and, second, the countries of the Gulf of
Guinea, including Benin, Côte d’Ivoire, Ghana, Guinea,
Liberia, Nigeria, Sierra Leone and Togo, which make up
the humid region of Western Africa.

The climatic characteristics of the sub-region are
discussed in Chapter 2: Atmosphere. It is subject to
tropical climatic variations, resulting in high annual
temperatures and heavy rainfall which steadily decline
towards the Sahara Desert. Rainfall is of vital
importance in determining climate in tropical areas in
general, and in Western Africa in particular, because it
varies so widely from area to area and season to season
it represents a limiting factor for rain-fed agriculture,
which provides the economic base of the countries. In
the Sahel region, there is one rainy season, lasting
between two and five months, while the Gulf of Guinea
countries have two rainy seasons. Western Africa is
characterized by four types of climate (GRAIN 2002):

Sahelian climate: the rainy season lasts no longer
than three months; rainfall is irregular and does not
exceed 500 mm;

Sudanian climate: rainfall does not exceed 800 mm
in northern Nigeria, and is no more than 1 000 mm
in southern Mali; and

Equatorial climate: localized essentially along the
Gulf of Guinea, where rainfall can exceed 2 000 mm.

Market Forces scenario

In this scenario, agricultural production prevails over
the other sectors. This results in a market economy that
does not take environmental matters into account and
undermines government initiatives. Growing trade,
driven by the forces of globalization, results in more
extensive farming and an increase in the area of
cultivated land. Food production levels rise at the cost
of environmental considerations. Where necessary,
technology is brought into play to meet international
trade demands and production requirements. As a
consequence, soil erosion due to overproduction
worsens, and this situation is exacerbated because of
the increasing incidence of droughts.

Deforestation associated with high levels of GHG
emissions could cause acid rain, further contributing to
soil erosion. These changes have implications for food
security in Western Africa, particularly in the most
vulnerable region of the Sahel. Increasing
concentrations of GHG emissions in the atmosphere
affect climate variability, including shorter rainy
seasons, and lead in the long term to climate change.

Locust invasions increase due to climate change
continue to cause food deficits as no action is being
taken to reverse this. Consequently, the food situation
worsens in certain areas of Burkina Faso, Chad, Mali,
Mauritania, Niger and northern Senegal. The invasion of
the desert by locusts is a consequence of climate
variability. The unexpected rains provoke a proliferation
of locusts, which are normally in a state of dormancy
(FAO 2004). The changing climate (in this case an
upsurge in rainfall) cause the disruption of this dormant
state. Damage to millet crops and grazing land
attributable to such agro-climatic conditions has been
recorded throughout Cape Verde and on a more
localized scale in Burkina Faso, Mali, Mauritania, Niger
and Senegal (FAO 2005a). This trend is likely to worsen.

Accordingly, the overall production of cereals (millet
and sorghum), the largest food crops of this part of
Africa, declines, increasing food insecurity and affecting
prices for consumers. Even the coastal countries (Gulf of
Guinea, humid Western Africa), which have until now
enjoyed a certain measure of climate security
(abundant rainfall), see their resources dwindle under
the influence of environmental degradation and they
too become vulnerable. Decreased rainfall and
increased evaporation linked to high temperatures
leads to water shortages and deterioration in water
resources. Hydrological imbalances cause the collapse
of certain economic activities. Reduced river flows have
a negative impact on hydroelectric production. And,
hydroelectric energy production is affected in Benin,
Côte d’Ivoire, Ghana and Togo. This is a replica of the
events of February 1998, when Ghana faced an energy
crisis caused by a drop in the water level of Lake Volta
(Niasse and others 2004). Successive years of drought
continue to reduce the size of humid zones in many
regions. Despite some patchy rains, the general decline
in rainfall continues. Sporadic droughts affect river
systems, agricultural production, supplies of drinking
water and hydroelectric production.